控制性降压对鼻内镜手术视野及脑血流变化的影响

目的观察不同水平控制性降压对鼻内镜手术视野清晰度及脑血流的影响。方法将240例临床择期手术患者随机分成4组，每组60例。组1（G1）控制性降压水平为原平均动脉压的64%，组2（G2）为70%，组3（G3）为80%，组4（G4）未施降压，做为对照。采用频率为2?MHz的经颅多普勒脑血流速度仪测定大脑中动脉血流速率，同时根据Fromme术野质量评分表由同一术者进行术野质量评分。结果G1、G2、G3组平均动脉压降至原血压的64%、70%、80%，维持1?h，上述各组脑血流与对照组间差异无统计学意义，降至64%术野清晰度各组间及与对照组间差异有统计学意义。结论吸入性全麻下用0.01%硝普钠（SNP）+安氟醚（ENF）将血压降至原血压的64%，维持1h，在供氧充分的情况下，对脑血流量无明显影响，但术野清晰度最佳，该方法是安全有效的。

Effects of controlled hypotension at different levels on definition of surgical field and cerebral blood flow

To explore the effects of deliberate hypotension at different levels on cerebral blood flow and definition of surgical fields. Methods240 ASA Grade patients were randomly divided into four groups( 60 in each group ): group 1 whose mean arterial pressure(MAP) was 64% of the former, group 2 whose MAP was 70% of the former, group 3 whose MAP was 80% of the former and the control group. Cerebral blood flow during hypotension was determined by transcranial Doppler ultrasonography, meanwhile surgical field quality (SSFQ) scores were assessed based on the Fromme surgical field quality list. ResultHypotesion caused a light decrease in cerebral blood flow velocity (CBFV) but was not significantly different either among three groups or during the procedure. Conclusion64% MAP maintained for 1 hour has no significant effect on cerebral blood flow but gives the best definition of the surgical field.